Question

The masses of neutron and Proton are 1.0087 amu and 1.0073 amu respectively. It the neuron and Protons combins to form helium nucleus of mass 4.0015 amu then binding energy of the helium nucleus will be 

(A) 14.2 MeV 

(B) 28.4 MeV 

(C) 27.3 MeV 

(D) 20.8 MeV

Answer 1

The correct option is (B) 28.4 MeV.

Explanation:

Binding energy in amu = Δm = [m_rZ + m_n(A – Z)] – M

Helium nucleus contains 2 neutron and 2 protons.

∴ Δm = [2 × 1.0087 + 2 × 1.0073] – 4.0015 

= 0.0305 amu 

Binding energy E = Δm in amu × 931 MeV 

= 0.0305 × 931 

∴ E = 28.39 MeV.